Vulcan successfully launches Peregrine lunar lander on inaugural flight

by Aaron McCrea

United Launch Alliance (ULA) has done its part in returning the US to the Moon with the launch of Astrobotic’s Peregrine lunar lander atop its brand-new Vulcan Centaur rocket. 

Cert-1, The first-ever mission for Vulcan, lifted off on Monday, Jan. 8 at 2:18 AM EST (7:18 AM UTC) during a 45-minute launch window. It took off out of Space Launch Complex(SLC) 41 at Cape Canaveral Space Force Station in Florida.

Vulcan was expected to fly in 2023 on Dec. 24, until routine problems with the ground equipment caused only a partial wet dress rehearsal (WDR). The chief executive of ULA, Tory Bruno said, “I’d like a FULL WDR before our first flight, so XMAS eve is likely out.”

This set the launch date to Jan. 8, 2024. Vulcan Centaur was rolled out 500 meters on the Vulcan Launch Platform on Friday, Jan. 5 for what was the final time before launch.


Vulcan Overview

After nearly a decade of development, Vulcan Centaur launched two payloads using the VC2S variant. The VC2S variant of Vulcan represents a Vulcan Centaur with two solid rocket boosters (SRB) and a standard fairing. This configuration can take Peregrine to the lunar surface and Enterprise Flight to deep space. 

Vulcan is a two-stage rocket that uses liquefied natural gas and liquid oxygen on the first stage and liquid hydrogen and liquid oxygen on Centuar V, the second stage. The first stage engines are two of Blue Origin’s BE-4 engines that have been in development since 2011. This will be BE-4’s first in-flight mission and will move ULA from Russian dependency with the RD-180 engines on Atlas V to American-made engines on Vulcan. 

Attached to the side of the booster are two graphite-epoxy motors (GEM) 63XL SRBs built by Northrup Grumman. These will be the longest monolithic SRBs ever flown and will be a considerable upgrade to the GEM 63 SRBs used on Atlas V.

The second stage will use two RL-10 engines built by Aerojet Rocketdyne. These are the same upper-stage engines that Atlas V used and are proven to be extremely reliable. The standard 15.5-meter payload fairings will be aerodynamically covering the payloads during assent until second-stage ignition where they will be jettisoned. 

Vulcan is 61.6 meters tall and 5.4 meters in diameter. It will weigh 663,367 kilograms when fully loaded on the launch pad, and will produce 8.9 meganewtons of thrust at liftoff. This flight of Vulcan will be heading to a Trans-lunar Injection(TLI) to get a payload to the Moon and then change to a heliocentric orbit. This means with the two SRB Vulcan will be able to deliver up to 6,300 kilograms to the Moon.

Flight Profile

ULA began loading the liquified natural gas, liquid hydrogen, and liquid oxygen propellant onto Vulcan late Jan. 7 to ensure full load by Jan.8 at 2:18 AM EST (7:18 AM UTC). 

Then, the BE-4 engines ignited right before liftoff at T-5 seconds and Vulcan started to gain altitude at T+1 second. It then began the pitch/yaw maneuver shortly after clearing the tower. 

Vulcan reached Mach one at T+1 minute and nine seconds before reaching max-Q or the maximum aerodynamic stress Vulcan will have to endure through its entire flight. Then around 35 seconds later, the GEM 63XL SRBs separated from the vehicle and were jettisoned. 

The BE-4 engines continued to burn until booster engine cutoff at T+ 4:59. Six seconds later, the first stage was done with flight and separated from the second stage. Centaur V then started its two RL-10 engines at T+5:15. Once the engines were lit, the fairings separated revealing the payloads at T+5:23. 

Centaur continued its initial burn for a little over 10 minutes until T+15:45 into flight. At this point, Vulcan entered a coast phase, which lasted until  T+43 minutes 35 seconds when the RL-10s relit for course correction to TLI. 

At T+47:37 the second stage shut down once again and coasted for just under three minutes. After this coast phase, the Peregrine lunar lander is placed in a highly elliptical orbit where it will then be released to intercept the Moon.

After Peregrine’s separation, Centaur relit one final time at T+1 hour 18 minutes and 24 seconds for 20 seconds to place Celestis Memorial Spaceflight’s ‘Enterprise Flight’ payload into a heliocentric orbit. The official mission end is anticipated at T+4:24:44

The flight profile for the Cert-1 mission. (Credit: ULA)

Enterprise Flight

Celestis Memorial Spaceflights are providing the opportunity to send DNA or cremated remains to deep space. The service called Voyager Memorial Spaceflight promises to send a piece of you or a loved one on a journey to 297 million kilometers into space. 

There was a memorial service and dinner for the friends family and loved ones who are sending their late friend or family member on one final journey before the launch on Monday.

Celestis Memorial Spaceflights have been around since 1997 and have launched on many different vehicles including Pegasus-XL, Falcon 1, Falcon 9, Falcon Heavy, and now have flown on Vulcan. Using Centaur V, ULA put the DNA and remains on a journey into deep space just as expected so they can rest among the stars. 

Peregrine Mission One

Astrobotic’s Peregrine lunar lander attempted to be one of the first US Moon landings since the end of the Apollo program. In 2019, Astrobotic was selected by NASA’s Commercial Lunar Payload Services (CLPS) and given a 79.5 million dollar contract to build Peregrine to study the Moon before humans return to it. 

The Peregrine lander beginning encapsulation inside the fairing. Credit: ULA)

Peregrine had 20 payloads on board, with five of them coming from NASA’s CLPS. These payloads include specific scientific projects with the main goals of looking for water ice in the lunar regolith and gaining more data on the radiation environment, the lunar exosphere, and the magnetic fields on the surface of the Moon. Some payloads are there to represent humanity with art and historical artifacts.

Around 40 minutes after separation from Centaur, Peregrine came to life and began receiving signals from Astrobotic’s mission control center in Pittsburgh, PA. There were small adjustment maneuvers that were performed in Earth’s orbit to check systems for Peregrine’s lunar landing that were successful. After those were confirmed, Peregrine tried to aim its solar panels toward the sun to charge its lithium-ion battery for the long coast to the Moon, but there was an anomaly that stopped it from performing the entire maneuver. 

After a known communications blackout, the Astrobotic team corrected the anomaly. However, it was found that there was a failure within the propulsion system. This failure caused a critical amount of propellant loss and caused the landing on the Moon to be aborted.

The best hypothesis of what went wrong came from Astrobotic on Tuesday, Jan. 9. It is believed that a valve failed to reseal which caused helium to increase the pressure in the oxidizer tank. This led to a rupture of the tank causing the propellant leak. They added that there is no evidence that the problem stemmed from Vulcan’s launch.

While the Moon landing has officially been aborted, the propellant as of 1:00 PM EST on Jan. 12 (18:00 UST) has increased from 48 hours to 56 hours due to Astrobotic’s engineers finding optimizations with Peregrine.  If trends keep heading in the way they have, there is a chance to extend the life expectancy even longer and that could get Peregrine to potentially crash land on the moon. This would be a great achievement for Astrobotic and they would get to gain even more data than they expected when the propellant failure began over four days ago.

Astrobotic announced that they are grateful for all the support from the spaceflight community saying, “This is what makes the space industry so special, that we unite in the face of adversity.  The combined effort of Astrobotic to keep Peregrine alive is one of the most accurate portrayals of the quote by Norman Vincent Peale, “Shoot for the Moon. Even if you miss, you’ll land among the stars”

(Lead image: Liftoff of Vulcan from SLC-41. Credit: Julia Bergeron for NSF)

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