Days after it suffered a critical malfunction, a private U.S. lunar lander ended its mission in a blaze of glory when the company operating it intentionally caused the spacecraft to break apart in Earth’s atmosphere.
The lander, called Peregrine, was built and operated by the Pittsburgh-based company Astrobotic, which had hoped to make history by performing the first commercial soft landing on the lunar surface. The spacecraft flew as part of NASA’s Commercial Lunar Payload Services (CLPS) initiative, which has encouraged private companies to build and operate their own lunar landers to deliver NASA supplies and instruments to the moon.
Launched on the flawless inaugural flight of a United Launch Alliance Vulcan Centaur rocket in the predawn hours of January 8, Peregrine carried six NASA instruments and other payloads, including a “lunar library” archive, human remains and lunar rovers. But soon after separating from its rocket, the spacecraft suffered a fuel leak that sent its propulsion system into turmoil. Astrobotic now suspects a valve failure caused a rush of high-pressure helium to flood into and rupture Peregrine’s fuel tank. The resulting jet of propellant that vented into space acted as an impromptu rocket that could have pushed the spacecraft into an irrecoverable tumble.
Quick-thinking Astrobotic engineers used Peregrine’s small control thrusters to counteract the jetting propellant, successfully stabilizing the spacecraft and pointing its solar panels toward the sun to charge onboard batteries. By that point, however, Peregrine had lost too much propellant to safely attempt a lunar landing.
From then on Astrobotic sought to keep the mission alive as long as possible, ultimately exceeding the company’s own expectations. As pressure within the ruptured tank fell over time, the spacecraft’s leak dwindled, extending its operations. On January 9 Astrobotic estimated that Peregrine had 40 hours’ worth of propellant remaining. Three days later the estimate was 52 hours. By January 15 the leak had “practically stopped,” according to a statement from the company.
Peregrine drifted out to the moon’s vicinity and reached more than 242,000 miles from Earth on January 13. Had things gone as planned, the spacecraft would have then arced back toward our planet and looped outward a second time for a lunar rendezvous. Instead, in consultation with NASA, Astrobotic decided on January 14 to minimize space debris by letting Peregrine burn up in Earth’s atmosphere.
Based on the last received telemetry from Peregrine, Astrobotic officials estimate that at approximately 4:04 P.M. EST on January 18 the lander broke apart in the skies above the South Pacific Ocean, some 1,500 miles off the eastern coast of Australia.
“What a wild adventure we were just on,” said Astrobotic CEO John Thornton in a press briefing on January 19, sharing the high highs and low lows of the brief mission. “We had an anomaly,” he added. “After that anomaly, we just had victory after victory after victory.”
Despite the mission’s failure to land on the moon, at least two of its payload providers support the decision to destroy Peregrine.
“Preserving cislunar space is critical for future space activities of human civilization. This decision will ensure future missions have unobstructed access to the space between Earth and the moon,” wrote Matthew Hoerl, co-founder of the Arch Mission Foundation, which supplied the lunar library archive for Peregrine, in an e-mail to Scientific American. “As the first U.S. commercial lunar lander to operate in space, we hope others follow this precedent-setting decision in the event of mission anomalies.”
Onward and Upward
Astrobotic’s mission may end up setting important precedents for CLPS, which will spend upward of $2.6 billion in the coming years to have NASA instruments delivered to the moon.
Unlike traditional NASA missions, in which the space agency owns and operates the hardware, CLPS missions are like lunar versions of UPS and FedEx: private delivery services. In exchange for giving up control over every mission detail, NASA hopes to save considerable money. In 2019 the agency paid Astrobotic $79.5 million to deliver several instruments onboard this mission—far less than NASA would have historically spent to build and operate its own lunar lander.
By catalyzing a commercial lunar delivery industry, NASA aims to spur more public and private entities to fly payloads to the moon. In addition to its NASA cargo, Peregrine Mission 1 was also flying a radiation detector from Germany, rovers contributed by Mexico and an array of payloads from paying private customers. But lower costs and higher access may also bring with them a greater risk of any given mission going wrong. As Scientific American has previously reported, NASA is running CLPS with an expectation that at least some missions will fail to reach the moon safely.
“Breakthrough innovation doesn’t tend to take place as a progressively positive series of events,” said Joel Kearns, deputy associate administrator for exploration at NASA’s Science Mission Directorate, at the January 19 press briefing. “Failure is often part of the road to success.”
Although Peregrine didn’t make it to the lunar surface, Astrobotic has won plaudits across the space industry for its transparency over the spacecraft’s health in the aftermath of its misfortune. Under CLPS, Astrobotic needed to keep NASA informed on mission updates, but not necessarily the public. According to Hoerl, however, the public received information from Astrobotic in near real time.
“They have flawlessly updated us when they did not need to on a mission that is otherwise a failure,” adds Laura Forczyk, founder and executive director of the space industry consulting firm Astralytical. “They made us rally around a lunar lander that was never going to land. Because of their frequent updates, they made us care.”
Peregrine also managed to conduct some science along the way. Astrobotic confirmed in a statement that all 10 of Peregrine’s powered payloads successfully received power from the spacecraft, which in some cases meant that instruments onboard could collect meaningful data. NASA reported that two of the agency’s payloads, a neutron spectrometer and a radiation sensor, managed to measure the radiation environment around Peregrine as it moved through interplanetary space.
“Spaceflight is an unforgiving environment, and we commend Astrobotic for its perseverance and making every viable effort to collect data and show its capabilities of Peregrine while in flight,” said Nicola Fox, associate administrator of NASA’s Science Mission Directorate, in a recent statement.
In addition, all nine of the payloads that were designed to communicate with Peregrine successfully returned data to Earth. Iris, a rover built by Carnegie Mellon University, sent back a “Hello Earth!” message. COLMENA, a set of five small rovers built by the Mexican Space Agency, also succeeded in sending data back—making it the first Mexican scientific instrument to operate in the moon’s vicinity.
CLPS’s next launch will come as soon as next month, when the Houston-based firm Intuitive Machines is scheduled to send off its IM-1 mission. IM-1 will attempt to land at a crater in the moon’s south polar region with 11 total payloads, including five for NASA. These missions are just the start: Astrobotic and Intuitive Machines already have their next missions booked to send scientific instruments to the moon’s south polar region in support of Artemis, NASA’s ambitious moon program.
During the postmission press briefing, Astrobotic’s Thornton said that the company’s next mission, the Griffin lander, is still targeting a launch near the end of this year and that Astrobotic will be thoroughly investigating Peregrine’s anomaly to ensure that it won’t affect future missions. Griffin is due to carry NASA’s Volatiles Investigating Polar Exploration Rover (VIPER), which is meant to look for water ice at the moon’s south pole.
Unlike the relatively brief crewed lunar forays of NASA’s Apollo program in 1960s and 1970s, the space agency envisions Artemis as a long-term effort that will see astronauts and robots visiting the moon for years, if not decades, to come. “We are trying hard to return to the surface of the moon sustainably,” Forczyk says. “It all ties together.”
Editor’s Note (1/19/24): This article has been updated to include comments from Astrobotic on the Peregrine mission’s conclusion, with additional reporting by Meghan Bartels.