biology

XS-1 (spacecraft)

XS-1 (spacecraft) is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand XS-1 (spacecraft) rather than just read about it. In short: The DARPA XS-1 was an experimental spaceplane/booster with the planned capability to deliver small satellites into orbit for the U.S. Department of Defense.

Key takeaways

XS-1 (spacecraft) belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect XS-1 (spacecraft) to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of XS-1 (spacecraft) from memory before moving on to harder problems.

Reference excerpt

The DARPA XS-1 was an experimental spaceplane/booster with the planned capability to deliver small satellites into orbit for the U.S. Department of Defense. It was reported to be designed to be reusable as frequently as once a day, with a stated goal of doing so for 10 days straight. The XS-1 was intended to directly replace the first stage of a multistage rocket by taking off vertically and flying to hypersonic speed and high suborbital altitude, enabling one or more expendable upper stages to separate and deploy a payload into low Earth orbit. The XS-1 would then return to Earth, where it could ostensibly be serviced fast enough to repeat the process at least once every 24 hours. The DARPA XS-1 program operated 2013–2020. After several years of refinement and proposals, in May 2017, the Defense Advanced Research Projects Agency (DARPA) selected Boeing for Phase 2/3 to build and test an XS-1 spacecraft (now called the Experimental Spaceplane program). At the time, test flights were scheduled to start no earlier than 2020. On 22 January 2020, it was announced that Boeing was ceasing its role in the program, effectively ending it.

History DARPA created the XS-1 program (later renamed to the Experimental Spaceplane Program), with the intent to increase national security by inventing a new, inexpensive, short-notice form of hypersonic aircraft. They promoted concepts such as reaching a Low Earth orbit within days, unmanned reusable rockets, external boosters being replaced by internal, self-contained cryogenic propelled boosters, the ability to deploy 900 to 3,000 lb (410 to 1,400 kg) payloads into polar orbit, composite-metallic wings that could withstand suborbital hypersonic flight and temperatures exceeding 3,000 °F (1,600 °C), autonomous flight technology developed by DARPA's Airborne Launch Assist Space Access (ALASA) program, and reaching Mach 10. The XS-1 program followed several previous failed attempts to develop a reusable space launch vehicle. The Rockwell X-30 in the 1980s and X-33 VentureStar in the 1990s never flew because of immature technologies. DARPA's last attempt was the Responsive Access, Small Cargo, Affordable Launch (RASCAL) program in the early 2000s with the goal of placing 300 lb (140 kg) payloads in orbit for less than $750,000. The XS-1 program was announced in November 2013 at a DARPA industry day. DARPA stated that the XS-1 was more feasible due to better technologies, including light and low-cost composite airframe and tank structures, durable thermal protection, reusable and affordable propulsion, and aircraft-like health management systems. Jess Sponable, the XS-1 program manager, spoke on February 5, 2014, at NASA's Future In-Space Operations group, stating, "The vision here is to break the cycle of escalating space system costs, enable routine space access and hypersonic vehicles." By July 2014, three companies were awarded contracts to design a demonstration vehicle. The selected companies were Boeing with Blue Origin, Masten Space Systems with XCOR Aerospace, and Northrop Grumman with Virgin Galactic. Unlike other DARPA programs that were handed off to parts of the United States military once proven successful, this initiative was designed from the start to be a direct partnership between the agency and industry. In August 2015, Boeing, Northrop Grumman, and Masten Space Systems all received additional funding from DARPA to continue their design concepts for Phase 1B of the program. As of 2015, the first XS-1 orbital mission was planned to occur as early as 2020. DARPA began Phase 2 of the XS-1 program in April 2016. In July 2016, DARPA stated that they believed "the time is right for a renewed effort, one that began in 2013/14, but [in 2016 was] ramped up through a solicitation process, allowing for several industry concepts to be created. Per the [solicitation] requirements, the winged craft [requirements would continue to need to] be capable of performing 10 flights in 10 days, with a payload capacity greater than 3,000 lbs for a cost of less than $5 million USD per flight." In May 2017, DARPA selected Boeing for Phase 2/3 to build and test the XS-1 (now called the Experimental Spaceplane program). The phase 2/3 contract included $146 million in DARPA funding and an unspecified contribution by the company. On 22 January 2020, DARPA announced that Boeing was pulling out of the XS-1 program "immediately" and effectively ending the program.

Program goals The goals of the program as of September 2013 were: The space plane must carry a 3,000–5,000 lb (1,400–2,300 kg) payload to low Earth orbit for less than a cost of US$5 million per flight, at a rate of 10 or more flights per year; at that time, launching that type of payload requires using an Orbital Sciences Corporation Minotaur IV expendable booster, priced at $55 million once per year.

hypersonic flight to Mach 10 (12,300 km/h) or higher fast one-day turnaround time, including flying 10 times in 10 days a 1,800 kg (4,000 lb) payload on a trajectory to orbit launch cost less than 1/10 that of current launch systems, approximately US$5 million per flight uncrewed vehicle use a reusable first stage booster to fly at hypersonic speeds to a suborbital altitude, coupled with one or more expendable upper stages that would separate and deploy a satellite

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with XS-1 (spacecraft)

Start with the simplest possible case. Write down what XS-1 (spacecraft) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to XS-1 (spacecraft) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about XS-1 (spacecraft) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of XS-1 (spacecraft)

In research: XS-1 (spacecraft) appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses XS-1 (spacecraft) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: XS-1 (spacecraft) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cancelled American spaceplanes, Cancelled reusable launch systems, DARPA projects, so understanding it makes those chapters shorter.
In everyday life: Look for XS-1 (spacecraft) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study XS-1 (spacecraft) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what XS-1 (spacecraft) means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain XS-1 (spacecraft) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is XS-1 (spacecraft) in simple terms?

The DARPA XS-1 was an experimental spaceplane/booster with the planned capability to deliver small satellites into orbit for the U.S. Department of Defense.

Why does XS-1 (spacecraft) matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study XS-1 (spacecraft)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on XS-1 (spacecraft).