<snip />Well, I'm not so sure. In the past there have been quite a lot of, admittedly rather out of date, renders of a Dreamchaser being launched off Roc. At the very least they at one point thought it was possible.Here's a NASASpaceflight article about Dreamchaser on Roc from 2014: https://www.nasaspaceflight.com/2014/10/dream-chaser-eyes-rides-with-under-review-stratolaunch-system/Image bellow is the render from that time:<snip />I suspect that if you go with an all hydrolox launcher design, it might just barely be possible to build rocket that can launch Dreamchaser from Roc. It would certainly explain Stratolaunch's design decisions back when they were working on the PGA engine; it was a fuel-rich staged combustion hydrolox booster engine, about the size of Merlin 1D. Perfect for making your launch vehicle as light, when fueled, as can be managed. Please note that this is all purely vibes/it's-what-make-sense-to-me based. I haven't actually sat down and done the math for it.
<snip />Note the rocket shown was called the Pegasus II, in development by Orbital (prior to their merger with ATK) in partnership with Stratolaunch. It was a 3 stage rocket, the first two stages were solid rocket motors, and the third stage was hydrolox, powered by one or two RL-10 engines. It had a payload capacity of 13,500 lb (6.1 metric tons) to LEO. The DreamChaser to be launched was a 75% scale variant designed to be capable of flying 3 passengers or cargo. Additional info: the Pegasus II solid rocket motors were the same diameter as the Shuttle SRB but had a carbon composite casing and a more energetic propellant mix. The first stage (which had two short wings and a V tail) was intended to be recoveable after splashdown. The design was modified in late 2014 to use all solid rocket motors. However, the economic / business case for it never closed, so development was shelved, and later abandoned altogether.
Sierra Space describes long-term plans for Dream Chaser and inflatable modules:https://spacenews.com/sierra-space-describes-long-term-plans-for-dream-chaser-and-inflatable-modules/https://twitter.com/SpaceNews_Inc/status/1674017635472748546
Quote from: yg1968 on 06/28/2023 02:44 pmSierra Space describes long-term plans for Dream Chaser and inflatable modules:https://spacenews.com/sierra-space-describes-long-term-plans-for-dream-chaser-and-inflatable-modules/https://twitter.com/SpaceNews_Inc/status/1674017635472748546I see they mention horizontal takeoff in the context of ending dependence on third-party launch vehicles...
As Sierra Space continues to prepare for the first flight of its Dream Chaser vehicle, it is outlining long-term ambitions for both that vehicle and space station modules
We’re thinking about investigating the right technologies in thermal and propulsion and materials that allows us to potentially think about the staging options that would allow us, for the first time, have horizontal takeoff
QuoteAs Sierra Space continues to prepare for the first flight of its Dream Chaser vehicle, it is outlining long-term ambitions for both that vehicle and space station modules.The headline says plans but the article more accurately describes it as ambitions.QuoteWe’re thinking about investigating the right technologies in thermal and propulsion and materials that allows us to potentially think about the staging options that would allow us, for the first time, have horizontal takeoffMy BS meter is way way up on this. I'm thinking of considering to investigate the possibility of believing any of this.
For the Technical Approach evaluation, Sierra Space’s proposed technical approach demonstrated overall competence to achieving the proposed capability. Its capability concept received a significant strength for its integrated LEO transportation, destination, and infrastructure capabilities that utilize DC-200, Pathfinder, and other elements.
For the Technical Approach evaluation, there was one new significant strength for engaging with industry partners for alternative transportation options to service Pathfinder and increase flexibility and availability of access.
https://www.nasa.gov/jsc/procurement/ccsc2Quote from: Philip R. McAlisterFor the Technical Approach evaluation, Sierra Space’s proposed technical approach demonstrated overall competence to achieving the proposed capability. Its capability concept received a significant strength for its integrated LEO transportation, destination, and infrastructure capabilities that utilize DC-200, Pathfinder, and other elements. Emphasis mine.What does Pathfinder refer to? Is that the name of the first DC-200 and I somehow missed that? Can't find any other references to the name. Edit: It is certainly not the name of the first DC-200, not sure what to make of it. Emphasis mine.:Quote from: Philip R. McAlisterFor the Technical Approach evaluation, there was one new significant strength for engaging with industry partners for alternative transportation options to service Pathfinder and increase flexibility and availability of access.
https://www.businesswire.com/news/home/20230615828732/en/Sierra-Space-Awarded-Space-Act-Agreement-with-NASA"This SAA award by NASA provides support to a “pathfinder” space station, which serves as a technology demonstration for key elements of commercial space stations. Such demonstrations are vital steps to ultimately designing objects intended for sustained commercial habitation in orbit. The SAA is set to begin while the systems are in the design and development phases and last for five years – through on-orbit deployment later this decade." <snip />
Quote from: BrightLight on 07/12/2023 07:43 pmhttps://www.businesswire.com/news/home/20230615828732/en/Sierra-Space-Awarded-Space-Act-Agreement-with-NASA"This SAA award by NASA provides support to a “pathfinder” space station, which serves as a technology demonstration for key elements of commercial space stations. Such demonstrations are vital steps to ultimately designing objects intended for sustained commercial habitation in orbit. The SAA is set to begin while the systems are in the design and development phases and last for five years – through on-orbit deployment later this decade." <snip />Thanks - I think the capitalization of "Pathfinder" threw me off.
While discussing Sierra Space’s proposal during the selection meeting, I noted that there are synergies with Orbital Reef, but enough differences that I see value in providing support to the development of Sierra Space’s Pathfinder station and DC-200 crew transportation system.
Dream Chaser vs Space Shuttle: A Side-by-Side ComparisonJULY 21, 2023 | BLOGWhen most people think of space travel, they likely think of space shuttles. What they don’t realize is that these were a specific type of reusable spacecraft only used by NASA from 1981 until 2011.More than a decade ago today, on July 21, 2011, the last space shuttle mission landed at the legendary facility in the heart of Florida’s “Space Coast.” As Atlantis landed for the final time so too concluded the chapter in NASA’s 30-year shuttle program.The historic runway at Kennedy Space Center has remained largely quiet since – for too long – as humanity lost the ability to return from space with a low-G runway landing and we bid farewell to an icon of spaceflight.But that’s about to change.Sierra Space is dedicated to bringing the Kennedy Space Center runway back to life and ushering in the next era of space exploration with its revolutionary fleet of Dream Chaser® spaceplanes.The Dream Chaser is the first-ever winged commercial spaceplane, and although it looks somewhat like NASA’s space shuttle, it’s something entirely new. It’s also unlike Boeing’s X-37b, which exclusively conducts military missions, in that it will open shared access to space and international collaboration for all humankindSo, how does a Dream Chaser spaceplane vary from the traditional space shuttles we’re familiar with? Let’s explore the big differences.Design and ConfigurationNASA’s original space shuttle had a wing design much like an airplane. Instead of being independent and perched atop a rocket, it was integrated with an external fuel tank that provided fuel for its main engines and had two solid rocket boosters attached at the sides. Each space shuttle was designed to fly at least 100 missions – but they actually flew fewer than that.The first model of the DC-100 cargo variant Dream Chaser is named Tenacity. Tenacity represents an uncrewed spiritual successor to the space shuttle, and at 30 feet (9 meters) long, it’s roughly a quarter of the total length of the space shuttle orbiters – though the habitable volume is about half the space shuttle.The shuttle was 67 cubic meters (not including the airlock), and Tenacity’s pressurized volume is 33 cubic meters (including both the spaceplane and the cargo module). This makes the spaceplane more sustainable and easier to maneuver, but it also assists with gentle 1 g runway landings – ideal for fragile cargo.Dream Chaser, Tenacity, was originally designed as a crewed spaceplane, partially under NASA’s Commercial Crew Program, before being awarded a NASA Commercial Resupply Services 2 contract. Under this contract, the Dream Chaser spaceplane fleet (including Tenacity), will provide a minimum of seven uncrewed cargo service missions to and from the International Space Station (ISS) and will be designed with high reusability in mind.Launch and Reentry ProceduresLaunchingSierra Space Dream Chaser LaunchSpace shuttles were launched vertically on a launch pad, utilizing solid rocket boosters (SRBs) and main engines. Thus, shuttles needed 7.8 million pounds of thrust to reach orbit. The SRBs collectively provided 6.6 million pounds of thrust on top of the main shuttle engines, which added a total of 1.2 million pounds of thrust. The SRBs were jettisoned just after two minutes into the flight and the main engine cutoff would happen around eight minutes into the flight.In comparison, Tenacity is compatible with a wide variety of launch vehicles (rockets) and will be launched in a stowed configuration inside a payload fairing. This makes Tenacity significantly more flexible and reduces ascent loads on the vehicle compared to the space shuttle.With Tenacity in a payload fairing, it will sit on top of the rocket which will help protect the vehicle from debris. Sierra Space’s DC-200 crewed spaceplane variant will be launched in a similar configuration but without a fairing, which will still offer protection from debris since the rocket will be located below the vehicle.ReentryBack in the day, space shuttles executed controlled reentries into Earth’s atmosphere, entering nose-first at a high angle of attack to generate aerodynamic lift. Apollo astronauts were subjected to forces between 3-7 g’s though the shuttle missions saw less than 2 g’s on reentry.As mentioned earlier, the Tenacity can return critical cargo to Earth at less than 1 g, contributing to a gentle and safe landing for the craft and its potential crew.Of course, great leaps in tech don’t always happen smoothly. The Tenacity conquered tremendous challenges in its development, including early flight failures. Another big issue was figuring out how to demonstrate the spaceplane’s unique lifting body design ability to return to Earth with a smooth, low-G re-entry.In 2017, Sierra Space conducted a pivotal test flight. NASA and other stakeholders needed to see that these capabilities were possible outside of computer simulations – so the Sierra Space team tested the hardware during a real, autonomously conducted atmospheric flight.During the test, the spaceplane entered a 70-degree dive, quickly gaining airspeed to intercept its flight path for a normal Earth return. It performed flawlessly, autonomously deploying its landing gear, flaring, and touching down safely on a runway. Payload and CapacitySpace shuttles had large payload bays that could carry a variety of cargo, including military and defense satellites, scientific instruments, and even entire space station modules. These payloads weighed up to 27,500 kilograms (60,600 pounds) in low-Earth orbit missions.With the help of Sierra Space’s Shooting Star™ service module, the Tenacity spaceplane can deliver 5,500 kilograms (up to 12,000 pounds) of pressurized and unpressurized cargo to the space station before returning to Earth. Thanks to its internally developed thrusters with three different thrust modes, it can nimbly maneuver in space and ensure deliveries are effectively completed.Although this payload is smaller, the spaceplane is highly customizable for a range of applications. The Tenacity is a multi-mission vehicle that can provide faster turnarounds and handle more lifetime loads.Three separate NASA astronaut crews have visited the Sierra Space facilities to train on loading and unloading cargo in anticipation of Dream Chaser deliveries to the ISS.The Future of Dream ChaserThe Dream Chaser fleet is multi-mission, capable of supporting a variety of low-Earth orbit needs and promising greater efficiencies with high reusability and fast turnaround times. Its customizability makes it ideal for domestic and international customers, as does its flexibility regarding launch site, space destination, mission duration, and landing site.Tenacity will soon make its maiden voyage to deliver cargo to the ISS as part of its NASA CRS-2 contract. When it does, it will mark the beginning of a new era for space exploration globally (and beyond).Learn more about Sierra Space and consider joining the team bringing about the Orbital Age TM.
Illustration of Sierra Space's Dream Chaser spaceplane on reentry
Sierra Space's Dream Chaser spaceplane landing on runway
Illustration of Sierra Space's Dream Chaser spaceplane cargo
Before avionics were installed, the internal structure of Dream Chaser had visible gold composite of aluminum foil and other materials. This is used as a leakage liner to prevent oxygen from leaking out of the vehicle and maintain optimal pressure in the cabin.
Dream Chaser's Russian cousin:Quote from: Vahe231991 on 07/29/2023 03:45 am
More like ancestor. DC can trace its heritage to this vehicle via NASA attempts to copy it.Russians would've been better off making BOR into small manned spaceplane than trying to copy NASA's Shuttle. Being able to land at runway is lot better than trying retrieve Soyuz from wilderness in Russian winter.
All stuff I read had BOR first, nice to know USA had idea first.
