space launch system

nasa-says-orion’s-heat-shield-is-good-to-go-for-artemis-ii—but-does-it-matter?

NASA says Orion’s heat shield is good to go for Artemis II—but does it matter?

artemis, artemis II, bill nelson, human spaceflight, moon, NASA, orion, space launch system, Uncategorized / /

“We have since determined that while the capsule was dipping in and out of the atmosphere, as part of that planned skip entry, heat accumulated inside the heat shield outer layer, leading to gases forming and becoming trapped inside the heat shield,” said Pam Melroy, NASA’s deputy administrator. “This caused internal pressure to build up and led to cracking and uneven shedding of that outer layer.”

An independent team of experts concurred with NASA’s determination of the root cause, Melroy said.

NASA Administrator Bill Nelson, Deputy Administrator Pam Melroy, Associate Administrator Jim Free, and Artemis II Commander Reid Wiseman speak with reporters Thursday in Washington, DC. Credit: NASA/Bill Ingalls

Counterintuitively, this means NASA engineers are comfortable with the safety of the heat shield if the Orion spacecraft reenters the atmosphere at a slightly steeper angle than it did on Artemis I and spends more time subjected to higher temperatures.

When the Orion spacecraft climbed back out of the atmosphere during the Artemis I skip reentry, a period known as the skip dwell, NASA said heating rates decreased and thermal energy accumulated inside the heat shield’s Avcoat material. This generated gases inside the heat shield through a process known as pyrolysis. 

“Pyrolysis is just burning without oxygen,” said Amit Kshatriya, deputy associate administrator of NASA’s Moon to Mars program. “We learned that as part of that reaction, the permeability of the Avcoat material is essential.”

During the skip dwell, “the production of those gases was higher than the permeability could tolerate, so as a result, pressure differential was created. That pressure led to cracks in plane with the outer mold line of the vehicle,” Kshatriya said.

NASA didn’t know this could happen because engineers tested the heat shield on the ground at higher temperatures than the Orion spacecraft encountered in flight to prove the thermal barrier could withstand the most extreme possible heating during reentry.

“What we missed was this critical region in the middle, and we missed that region because we didn’t have the test facilities to produce the low-level energies that occur during skip and dwell,” Kshatriya said Thursday.

During the investigation, NASA replicated the charring and cracking after engineers devised a test procedure to expose Avcoat heat shield material to the actual conditions of the Artemis I reentry.

So, for Artemis II, NASA plans to modify the reentry trajectory to reduce the skip reentry’s dwell time. Let’s include some numbers to help illustrate the difference.

The distance traveled by Artemis I during the reentry phase of the mission was more than 3,000 nautical miles (3,452 miles; 5,556 kilometers), according to Kshatriya. This downrange distance will be limited to no more than 1,775 nautical miles (2,042 miles; 3,287 kilometers) on Artemis II, effectively reducing the dwell time the Orion spacecraft spends in the lower heating regime that led to the cracking on Artemis I.

NASA’s inspector general report in May included new images of Orion’s heat shield that the agency did not initially release after the Artemis I mission. Credit: NASA Inspector General

With this change, Kshatriya said NASA engineers don’t expect to see the heat shield erosion they saw on Artemis I. “The gas generation that occurs during that skip dwell is sufficiently low that the environment for crack generation is not going to overwhelm the structural integrity of the char layer.”

For future Orion spaceships, NASA and its Orion prime contractor, Lockheed Martin, will incorporate changes to address the heat shield’s permeability problem.

Waiting for what?

NASA officials discussed the heat shield issue, and broader plans for the Artemis program, in a press conference in Washington on Thursday. But the event’s timing added a coat of incredulity to much of what they said. President-elect Donald Trump, with SpaceX founder Elon Musk in his ear, has vowed to cut wasteful government spending.

NASA says Orion’s heat shield is good to go for Artemis II—but does it matter? Read More »

nasa-is-stacking-the-artemis-ii-rocket,-implying-a-simple-heat-shield-fix

NASA is stacking the Artemis II rocket, implying a simple heat shield fix

artemis, artemis II, human spaceflight, Kennedy Space Center, NASA, orion, Science, Space, space launch system, vehicle assembly building / /

A good sign

The readiness of the Orion crew capsule, where the four Artemis II astronauts will live during their voyage around the Moon, is driving NASA’s schedule for the mission. Officially, Artemis II is projected to launch in September of next year, but there’s little chance of meeting that schedule.

At the beginning of this year, NASA officials ruled out any opportunity to launch Artemis II in 2024 due to several technical issues with the Orion spacecraft. Several of these issues are now resolved, but NASA has not released any meaningful updates on the most significant problem.

This problem involves the Orion spacecraft’s heat shield. During atmospheric reentry at the end of the uncrewed Artemis I test flight in 2022, the Orion capsule’s heat shield eroded and cracked in unexpected ways, prompting investigations by NASA engineers and an independent panel.

NASA’s Orion heat shield inquiry ran for nearly two years. The investigation has wrapped up, two NASA officials said last month, but they declined to discuss any details of the root cause of the heat shield issue or the actions required to resolve the problem on Artemis II.

These corrective options ranged from doing nothing to changing the Orion spacecraft’s reentry angle to mitigate heating or physically modifying the Artemis II heat shield. In the latter scenario, NASA would have to disassemble the Orion spacecraft, which is already put together and is undergoing environmental testing at Kennedy Space Center. This would likely delay the Artemis II launch by a couple of years.

In August, NASA’s top human exploration official told Ars that the agency would hold off on stacking the SLS rocket until engineers had a good handle on the heat shield problem. There are limits to how long the solid rocket boosters can remain stacked vertically. The joints connecting each segment of the rocket motors are certified for one year. This clock doesn’t actually start ticking until NASA stacks the next booster segments on top of the lowermost segments.

However, NASA waived this rule on Artemis I when the boosters were stacked nearly two years before the successful launch.

A NASA spokesperson told Ars on Wednesday that the agency had nothing new to share on the Orion heat shield or what changes, if any, are required for the Artemis II mission. This information should be released before the end of the year, she said. At the same time, NASA could announce a new target launch date for Artemis II at the end of 2025, or more likely in 2026.

But because NASA gave the “go” for SLS stacking now, it seems safe to rule out any major hardware changes on the Orion heat shield for Artemis II.

NASA is stacking the Artemis II rocket, implying a simple heat shield fix Read More »

rocket-delivered-to-launch-site-for-first-human-flight-to-the-moon-since-1972

Rocket delivered to launch site for first human flight to the Moon since 1972

artemis, artemis II, human spaceflight, Kennedy Space Center, NASA, Science, SLS core stage, Space, space launch system / /
Rocket delivered to launch site for first human flight to the Moon since 1972

The central piece of NASA’s second Space Launch System rocket arrived at Kennedy Space Center in Florida this week. Agency officials intend to start stacking the towering launcher in the next couple of months for a mission late next year carrying a team of four astronauts around the Moon.

The Artemis II mission, officially scheduled for September 2025, will be the first voyage by humans to the vicinity of the Moon since the last Apollo lunar landing mission in 1972. NASA astronauts Reid Wiseman, Victor Glover, Christina Koch, and Canadian mission specialist Jeremy Hansen will ride the SLS rocket away from Earth, then fly around the far side of the Moon and return home inside NASA’s Orion spacecraft.

“The core is the backbone of SLS, and it’s the backbone of the Artemis mission,” said Matthew Ramsey, NASA’s mission manager for Artemis II. “We’ve been waiting for the core to get here because all the integrated tests and checkouts that we do have to have the core stage. It has the flight avionics that drive the whole system. The boosters are also important, but the core is really the backbone for Artemis. So it’s a big day.”

The core stage rolled off of NASA’s Pegasus barge at Kennedy early Wednesday, following a weeklong ocean voyage from New Orleans, where Boeing builds the rocket under contract to NASA.

Ramsey told Ars that ground teams hope to begin stacking the rocket’s two powerful solid rocket boosters on NASA’s mobile launcher platform in September. Each booster, supplied by Northrop Grumman, is made of five segments with pre-packed solid propellant and a nose cone. All the pieces for the SLS boosters are at Kennedy and ready for stacking, Ramsey said.

The SLS upper stage, built by United Launch Alliance, is also at the Florida launch site. Now, the core stage is at Kennedy. In August or September, NASA plans to deliver the two remaining elements of the SLS rocket to Florida. These are the adapter structures that will connect the core stage to the upper stage, and the upper stage to the Orion spacecraft.

A heavy-duty crane inside the cavernous Vehicle Assembly Building (VAB) will hoist each segment of the SLS boosters into place on the launch platform. Once the boosters are fully stacked, ground teams will lift the 212-foot (65-meter) core stage vertical in the transfer aisle running through the center of the VAB. A crane will then lower the core stage between the boosters. That could happen as soon as December, according to Ramsey.

Then comes the launch vehicle stage adapter, the upper stage, the Orion stage adapter, and finally, the Orion spacecraft itself.

Moving toward operations

NASA’s inspector general reported in 2022 that NASA’s first four Artemis missions will each cost $4.1 billion. Subsequent documents, including a Government Accountability Office report last year, suggest the expendable SLS core stage is responsible for at least a quarter of the cost for each Artemis flight.

The core stage for Artemis II is powered by four hydrogen-fueled RS-25 engines produced by Aerojet Rocketdyne. Two of the reusable engines for Artemis II have flown on the space shuttle, and the other two RS-25s were built in the shuttle era but never flew. Each SLS launch will put the core stage and its engines in the Atlantic Ocean.

Steve Wofford, who manages the stages office for the SLS program at NASA’s Marshall Space Flight Center, told Ars there are “no major configuration differences” between the core stages for Artemis I and Artemis II. The only minor differences involve instrumentation that NASA wanted on Artemis I to measure pressures, accelerations, vibrations, temperatures, and other parameters on the first flight of the Space Launch System.

“We are still working off some flight observations that we made on Artemis I, but no showstoppers,” Wofford said. “On the first article, the test flight, Artemis I, we really loaded it up. That’s a golden opportunity to learn as much as you can about the vehicle and the flight regime, and anchor all your models… As you progress, you need less and less of that. So Core Stage 2 will have less development flight instrumentation than Core Stage 1, and then Core Stage 3 will have less still.”

Rocket delivered to launch site for first human flight to the Moon since 1972 Read More »

rocket-report:-firefly’s-ceo-steps-down;-artemis-ii-core-stage-leaves-factory

Rocket Report: Firefly’s CEO steps down; Artemis II core stage leaves factory

astra, china, Commercial space, Firefly Aerospace, launch, long march, NASA, rocket report, Science, Space, space launch system, spacex, starship / /

Vaya con dios —

Rocket Factory Augsburg completed qualification of its upper stage for a first launch this year.

–

The core stage for NASA's second Space Launch System rocket rolls aboard a barge that will take it from New Orleans to Kennedy Space Center in Florida.

Enlarge / The core stage for NASA’s second Space Launch System rocket rolls aboard a barge that will take it from New Orleans to Kennedy Space Center in Florida.

Welcome to Edition 7.03 of the Rocket Report! One week ago, SpaceX suffered a rare failure of its workhorse Falcon 9 rocket. In fact, it was the first time the latest version of the Falcon 9, known as the Block 5, has ever failed on its prime mission after nearly 300 launches. The world’s launch pads have been silent since the grounding of the Falcon 9 fleet after last week’s failure. This isn’t surprising, but it’s noteworthy. After all, the Falcon 9 has flown more this year than all of the world’s other rockets combined and is fundamental to much of what the world does in space.

As always, we welcome reader submissions. If you don’t want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets as well as a quick look ahead at the next three launches on the calendar.

Astra finally goes private, again. A long-simmering deal for Astra’s founders to take the company private has been finalized, the company announced Thursday, capping the rocket launch company’s descent from blank-check darling to delisting in three years, Bloomberg reports. The launch company’s valuation peaked at $3.9 billion in 2021, the year it went public, and was worth about $12.2 million at the end of March, according to data compiled by Bloomberg. Astra’s chief executive officer, Chris Kemp, and chief technology officer, Adam London, founded the company in 2016 with the goal of essentially commoditizing launch services for small satellites. But Astra’s rockets failed to deliver and fell short of orbit five times in seven tries.

Spiraling … Astra’s stock price tanked after the spate of launch failures, drying up its funding spigot as Kemp tried to pivot toward a slightly larger, more reliable rocket. Astra acquired a company named Apollo Fusion in 2021, entering a new business segment to produce electric thrusters for small satellites. But Astra’s launch business faltered, and last November Kemp and London submitted an offer to retake ownership of the company. Astra announced the closure of the take-private deal Thursday, with Kemp and London acquiring the company’s outstanding shares for 50 cents per share in cash, below the stock’s final listing price of 53 cents. “We will now focus all of our attention on a successful launch of Rocket 4, delivering satellite engines to our customers, and building a company of consequence,” Kemp said. (submitted by EllPeaTea and Ken the Bin)

Firefly chief leaves company. Launch startup Firefly Aerospace parted ways with CEO Bill Weber, Payload reports. The announcement of Weber’s departure late Wednesday came two days after Payload reported Firefly was investigating claims of an alleged inappropriate relationship between him and a female employee. “Firefly Aerospace’s Board of Directors announced that Bill Weber is no longer serving as CEO of the company, effective immediately,” the company said in a statement Wednesday night. Peter Schumacher takes over as interim CEO while Firefly searches for a new permanent chief executive. Schumacher was an interim CEO at Firefly before Weber’s hiring in 2022.

Two days and gone … Payload published the first report of Weber’s alleged improper relationship with a female employee Monday. Two days later, Weber was gone. Payload reported an executive brought his concerns about the alleged relationship to Firefly’s board and resigned because he lost confidence in leadership at the company. Citing four current and former employees, Payload reported Firefly’s culture became “chaotic” since Weber took the helm in 2022 after its acquisition by AE Industrial Partners. The Texas-based company achieved some success during Weber’s tenure, with four orbital launches of its Alpha rocket, although two of the flights ended up in lower-than-planned orbits. (submitted by Ken the Bin)

The easiest way to keep up with Eric Berger’s space reporting is to sign up for his newsletter, we’ll collect his stories in your inbox.

Themis hop tests delayed to next year. The initial hop tests of the European Themis reusable booster, developed by ArianeGroup and funded by ESA, won’t start until next year, European Spaceflight reports. The Swedish Space Corporation, which operates the space center in Sweden where Themis will initially fly, confirmed the schedule change. Once ArianeGroup moves on to higher altitude flights, the testing will be moved to the Guiana Space Center. ESA awarded the first development contract for the Themis booster in 2019, and the first hop tests were then scheduled for 2022. Themis’ hops will be similar to SpaceX’s Grasshopper rocket, which performed a series of up-and-down atmospheric test flights before SpaceX started recovering and reusing Falcon 9 boosters.

Fate of Themis … The Themis booster is powered by the methane-fueled Prometheus engine, also funded by ESA. A large European reusable rocket is unlikely to fly until the 2030s, but a subsidiary of ArianeGroup named MaiaSpace is developing a smaller partially reusable two-stage rocket slated to debut as soon as next year. The Maia rocket will use a modified Themis booster as its first stage. “As a result, for MaiaSpace, the continued and rapid development of the Themis program is essential to ensure it can hit its projected target of an inaugural flight of Maia in 2025,” European Spaceflight reports. (submitted by Ken the Bin)

Rocket Report: Firefly’s CEO steps down; Artemis II core stage leaves factory Read More »

rocket-report:-a-new-estimate-of-starship-costs;-japan-launches-spy-satellite

Rocket Report: A new estimate of Starship costs; Japan launches spy satellite

artemis, elon musk, impulse space, Japan, launch, Momentus, NASA, orbex, Space, space launch system, spacex, starship, tiangong, tianzhou / /

A bigger tug —

One space tug company runs into financial problems; another says go big or go home.

–

An H-IIA rocket lifts off with the IGS Optical-8 spy satellite.

Enlarge / An H-IIA rocket lifts off with the IGS Optical-8 spy satellite.

Mitsubishi Heavy Industries

Welcome to Edition 6.27 of the Rocket Report! This week, we discuss an intriguing new report looking at Starship. Most fascinating, the report covers SpaceX’s costs to build a Starship and how these costs will come down as the company ramps up its build and launch cadence. At the other end of the spectrum, former NASA Administrator Mike Griffin has a plan to get astronauts back to the Moon that would wholly ignore the opportunities afforded by Starship.

As always, we welcome reader submissions, and if you don’t want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets, as well as a quick look ahead at the next three launches on the calendar.

The problem at America’s military spaceports. The Biden administration is requesting $1.3 billion over the next five years to revamp infrastructure at the Space Force’s ranges in Florida and California, Ars reports. This will help address things like roads, bridges, utilities, and airfields that, in many cases, haven’t seen an update in decades. But it’s not enough, according to the Space Force. Last year, Cape Canaveral was the departure point for 72 orbital rocket launches, and officials anticipate more than 100 this year. The infrastructure and workforce at the Florida spaceport could support about 150 launches in a year without any major changes, but launch activity is likely to exceed that number within a few years.

Higher fees incoming … Commercial launch companies operating from Cape Canaveral Space Force Station, Florida, or Vandenberg Space Force Base, California, pay fees to the Space Force to reimburse for direct costs related to rocket launches. These cover expenses like weather forecast services, surveillance to ensure airplanes and boats stay out of restricted areas, and range safety support. “What that typically meant was anything we did that was specifically dedicated to that launch,” said Col. James Horne, deputy commander of the Space Force’s assured access to space directorate. This is about to change after legislation passed by Congress in December allows the Space Force to charge indirect fees to commercial providers. This money will go into a fund to pay for maintenance and upgrades to infrastructure used by all launch companies at the spaceports.

Momentus is running out of money. Momentus, a company that specializes in “last mile” satellite delivery services, announced on January 12 that it is running out of money and does not have a financial lifeline, CNBC reports. The company was once valued at more than $1 billion before going public via a Special Purpose Acquisition Company (SPAC) in 2021 but now has a market capitalization of less than $10 million. Momentus has developed a space tug called Vigoride, designed to place small satellites into bespoke orbits after deploying from a larger rocket on a rideshare mission, such as a SpaceX Falcon 9. Now, Momentus is abandoning plans for its next mission that was due for launch in March. In December, the company laid off about 20 percent of its workforce to reduce costs.

Fatal blow? … Momentus may have received a potentially fatal blow after losing the US Space Development Agency’s recent competition for 18 so-called Tranche 2 satellites, Aviation Week reports. Instead, the SDA made recent satellite manufacturing contract awards to Rocket Lab, L3Harris, Lockheed Martin, and Sierra Space. On Wednesday, Momentus announced it closed a $4 million stock sale. This should keep Momentus afloat for a while longer but won’t provide the level of capital needed to undertake any significant manufacturing or technical development work. (submitted by Ken the Bin)

The easiest way to keep up with Eric Berger’s space reporting is to sign up for his newsletter, we’ll collect his stories in your inbox.

Orbex may go bigger. UK-based launch startup Orbex hasn’t yet flown its small satellite launcher, called Prime, but is already looking at what’s next, according to reports by European Spaceflight and the Financial Times. New Orbex CEO Phil Chambers, who was officially appointed earlier this month, told the Financial Times that the company was already discussing the possibility of developing a larger vehicle. Speaking to European Spaceflight, Chambers described the business model to deliver orbital launch services with Prime as “robust.” Despite this, he admitted that the small launch industry was only a small sliver of the overall launch market.

Learning to walk before running … While future growth is on Orbex’s radar, its near-term focus is completing construction of a spaceport in Scotland, launching a maiden flight of Prime, and delivering on the six flights the company has already sold. The two-stage Prime rocket, fueled by “bio-propane,” will be capable of hauling a payload of approximately 180 kilograms (nearly 400 pounds) into low-Earth orbit. But Orbex has been shy about releasing updates on the progress of the Prime rocket’s development since unveiling a full-scale mock-up of the launch vehicle in 2022. Last year, the CEO who led Orbex since its founding resigned. Its most recent significant funding round was valued at 40.4 million pounds in late 2022. (submitted by Ken the Bin)

Rocket Report: A new estimate of Starship costs; Japan launches spy satellite Read More »