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Dream Chaser Arrives at KSC

Tenacity shortly after arrival at NASA’s Space Systems Processing Facility. Note the lack of black TPS tiles near the wings, nose, and underside of the spaceplane, sometimes with silver foil in their place. All of these gaps will need to be filled in before Dream Chaser is flightworthy.
Credit: NASA/Sierra Space

Sierra Space’s first Dream Chaser spaceplane, Tenacity, arrived at NASA’s Kennedy Space Center on May 20th, 2024, over five weeks after Space Scout’s last report on the vehicle’s progress. The long-awaited spacecraft is expected to perform its first flight to the International Space Station later this year, ahead of routine cargo flights in support of NASA’s Commercial Resupply Services. Commercial Resupply Services sees private companies SpaceX and Northrop Grumman perform regular cargo deliveries to the ISS using their respective Cargo Dragon and Cygnus spacecraft, a successful flight of Tenacity would see Sierra Space and the Dream Chaser spacecraft folded in, providing new capabilities and increased redundancy to the program. While the end is in sight for Tenacity’s lengthy and delayed pre-launch campaign, work is not over yet, and an exact date for Dream Chaser’s first flight has not been declared.

Following the remanifestation of Cygnus onto Falcon 9 after the War in Ukraine halted the production of the Antares 230+ rocket, all American resupply missions to the ISS ride on just one rocket. Dream Chaser will launch on ULA’s Vulcan-Centaur rocket, returning the ISS to a state where it is supported by two fully redundant cargo systems, making for a program more resistant to unexpected setbacks. Dream Chaser will deliver 7,800 pounds of cargo to the ISS, and because of Dream Chaser’s unique nature as a spaceplane, will be able to return up to 3,500 pounds of cargo from space, while providing a gentler ride for sensitive cargo than SpaceX’s Cargo Dragon. Dream Chaser can land at any runway capable of accommodating a Boeing 737 airliner. Shooting Star meanwhile is expended after each flight, and can carry up to 8,500 pounds to be disposed of when it burns up in Earth’s atmosphere.

Dream Chaser Tenacity was previously undergoing testing at NASA’s Armstrong Test Facility in Ohio, alongside its service module, named Shooting Star. Shooting Star provides power, propulsion, and docking for the Dream Chaser spaceplane during its journey to and immediate departure from the International Space Station. The vibrational test campaign was the first time these two elements were integrated in a vertical position, as they would be during launch on ULA’s Vulcan-Centaur rocket, and was completed. Dream Chaser, this time on its own, entered into NASA’s In Space Propulsion facility, where it was placed into a large vacuum chamber and exposed to the thermal challenges of the vacuum of space. While the spacecraft was originally set to launch in April 2024, getting through testing proved more challenging than expected, and Tenacity’s test campaign concluded on May 9th, 2024. Shooting Star arrived at Kennedy Space Center on the 11th of May, two weeks ahead of Tenacity itself. Based on comments made by Sierra Space CEO Tom Vice on April 5th, Dream Chaser arrived at Kennedy Space Center about three weeks behind schedule. With both sections now at NASA’s Space Systems Processing Facility, they have begun being processed for launch, which may prove to be a lengthy process in its own right.

Foremost, Dream Chaser and Shooting Star have some final rounds of testing to undergo at the Space Systems Processing Facility, described in NASA’s press release as “acoustic and electromagnetic interference and compatibility testing.” This testing round will not be as intensive or demanding as that which occurred prior to shipment, but is the next challenge the craft will face. The biggest open question for when Dream Chaser will be truly flight-ready is its heatshield. Headshields seem to be a common subject matter in 2024, with an Orion heat shield anomaly being partially behind a delay to Artemis II in January, and Starship breaking up on reentry over the Indian Ocean back in March. Sierra Space’s heatshield trouble is a little less nebulous; Tenacity’s heat shield simply is not done yet. Likely to save time to meet the originally planned April launch date, Tenacity was delivered to Armstrong Test Facility without its thermal protection system completed. Noticeable gaps could be seen on the wings, in released imagery, however the video included in NASA’s press release affords a glance at the spaceplane’s underside, the section that will face forward during reentry. While some TPS tiles are present, the majority of the space is occupied by silver foil in place of the ablative tiles, likely compensating for their absence during thermal testing. It is the completion of TPS installation, and whatever steps may be taken to verify the completed system, that currently present the biggest open question.

Tenacity sits atop Shooting Star as it did during integrated testing at the Armstrong Test Facility in Ohio, which has been completed.
Credit: Sierra Space

The final phase of pre-launch will be payload integration and encapsulation, where the vehicles will be fueled and vertically integrated atop the Vulcan-Centaur payload adapter, before the fairing is closed around them ahead of transportation to the launch pad. United Launch Alliance’s Vulcan-Centaur rocket has its own questions to contend with, though not the usual kind for the space launch industry.

Vulcan-Centaur’s next launch is currently Dream Chaser’s first flight, and is referred to as “Certification-2” or “Cert-2” for short. On Vulcan’s side of the equation, this second flight represents a critical test of functionalities required to begin providing launches for National Security missions, of which Vulcan has a considerable amount. Because of this, ULA and its parent companies, Lockheed Martin and Boeing, have been under considerable pressure to accelerate the Vulcan-Centaur program to full operational capacity, recently being hit by “postponement fees” from the US Air Force for schedule slips. 

This puts ULA in a difficult situation- while the launch vehicle is progressing on schedule for launch with the Cert-2 core stage nearing its finalization, Dream Chaser remains several months out. As stated in our previous article, Sierra Space CEO Tom Vice indicated a date around Q4 2024 for Dream Chaser’s first launch, alongside the fact that there have been schedule slips since, it is unlikely that Dream Chaser is going to be launching dramatically ahead of schedule. Recent pressure and encouragement to remanifest Cert-2 may force ULA to launch Dream Chaser on Vulcan-Centaur’s third flight or later. 

Sierra Space has indicated more recently they expect Dream Chaser to be ready for flight on October 1st 2024, meanwhile ULA has stated that if Dream Chaser was not ready by September, Vulcan Cert-2 would default to a backup mission. Furthermore it is worth noting ULA’s statement came prior to the recent wave of pressure from the Pentagon. While no remanifest for Cert-2 has been officially announced, considering circumstance plans to do so may already be in motion behind the scenes, it may be only a matter of time.

The third Vulcan core stage recently had the first of two Blue Origin-provided BE-4 engines delivered ahead of integration; these engines remain the pacing item for Vulcan’s production. Engine installation for Cert-2 progressed relatively quickly, with both engines being installed in the time since our previous writing. Assuming the second BE-4 engine is delivered in the next month or so, it may be possible to for ULA to fly Tenacity on Vulcan-Centaur’s third vehicle while maintaining its Q4 2024 launch date.\

Vulcan Cert-2’s core stage with twin BE-4 engines installed as shared by Tory Bruno on April 17th 2024 on X, formerly known as Twitter. Assuming work has maintained pace since, it’s likely that this booster is nearing the closeout phase of its production.
Credit: ULA/Tory Bruno.

While the specific timing for when we should expect Dream Chaser to have its first orbital flight remains in flux, it is nevertheless a major achievement and milestone for Sierra Space to have delivered the first Dream Chaser and Shooting Star spacecraft to Kennedy Space Center. The company has never operated a spacecraft like Dream Chaser on orbit before, and considering their recently announced satellite bus line and heavy involvement in Blue Origin’s Orbital Reef space station, may only be the beginning of a long and diverse legacy. While scheduling is always a complex task in the industry, and often creates some amount of conflict between the interests of different parties, ultimately it is safe, steady, and cautious development, testing, and processing that often yields the best results. If Sierra Space wants to achieve its goals, a successful first flight for Dream Chaser is more important than an immediate one.

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