astronomy

Roll Out Solar Array

Roll Out Solar Array is a astronomy 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 Roll Out Solar Array rather than just read about it. In short: The Roll Out Solar Array (ROSA) and its larger version ISS Roll Out Solar Array (iROSA) are lightweight, flexible power sources for spacecraft designed and developed by Redwire. This new type of solar array provides much more energy than traditional solar arrays at much less mass.

Key takeaways

Roll Out Solar Array belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Roll Out Solar Array to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Roll Out Solar Array from memory before moving on to harder problems.

Reference excerpt

The Roll Out Solar Array (ROSA) and its larger version ISS Roll Out Solar Array (iROSA) are lightweight, flexible power sources for spacecraft designed and developed by Redwire. This new type of solar array provides much more energy than traditional solar arrays at much less mass. Traditional solar panels used to power satellites are bulky, with heavy panels folded together using mechanical hinges. Given a space-bound payload is limited in its mass and volume by necessity, ROSA is 20 percent lighter (with a mass of 325 kg (717 lb)) and one-fourth the volume of rigid panel arrays with the same performance. ROSA is a flexible and rollable solar array that operates the same way a measuring tape unwinds on its spool. The new solar array design rolls up to form a compact cylinder for launch with significantly less mass and volume, potentially offering substantial cost savings as well as an increase in power for satellites. ROSA has a center wing made of a flexible material which support the strings of photovoltaic cells that produce electricity. Both the sides of the wing have a narrow arm that extends through the length of the wing to provide support to the array, called a high strain composite boom. The booms look like split tubes made of a stiff composite material, flattened and rolled up lengthwise. The array does not need any motor to unfurl. This is achieved using the potential energy stored in the booms that is released as each boom transitions from a coil shape to a straight support arm. The solar wings are then deployed due to strain energy in rolled booms that are present at the two ends of the structure.

Patent Brian R. Spence and Stephen F. White were the first persons to patent the idea of the Roll Out Solar Array on January 21, 2010. They received a patent for this work on April 1, 2014.

History on ISS

ROSA test mission

NASA tested the ROSA technology in vacuum chambers on Earth throughout the 2010s and, satisfied by the promising results, commenced to test it in space on June 18 of 2017. ROSA launched aboard SpaceX CRS-11 on 3 June. Over the weekend of June 17–18, 2017, engineers on the ground remotely operated the International Space Station's robotic Canadarm2 to extract the Roll Out Solar Array (ROSA) experiment from the SpaceX Dragon resupply ship. After the observation the mechanism was not planned to be retrieved back to earth. The solar array unfurled June 18, extending by tensioning booms on both sides of the 1.6-meter-wide wing. NASA decided to conduct continuous tests for a week and observe its consequences. Engineers observed the behavior of the solar array as it was exposed to extreme temperature swings through the ISS's orbit. Vibrations and oscillations were also mechanically introduced to assess the array's response to structural loads. Subsequent to the experiments, ground controllers were unable to lock the solar panel in its stowed configuration. The solar array was therefore jettisoned from the International Space Station on June 30, following the 12-day test.

iROSA 2B/4B

In June 2021, two new solar iROSA panels were installed on the International Space Station's P6 truss mast cans. The two operations took six hours each to complete and were carried out on three spacewalks by astronauts Shane Kimbrough and Thomas Pesquet. The new arrays were intended to give the station a total of 120 kilowatts of additional augmented power during daytime orbit.

iROSA 3A/4A On 3 December 2022, Expedition 68 crew members Josh Cassada and Frank Rubio installed an iROSA at Array 3A on the S4 truss segment and connected it to the US power system. The spacewalkers undid bolts and installed cables and at 17:37 GMT the array was deployed and is receiving power. As part of get-ahead tasks, they prepared the 4A array on the P4 truss segment for the next spacewalk, demated the 1B array on the S6 segment, broke torque on the P4 electronics boxes, and installed cables along the truss to be mated at the end of the fifth spacewalk of the expedition. The spacewalk faced a delay when Cassada's suit did not power up. Troubleshooting steps were carried out and power was restored to Cassada's suit so they could continue the spacewalk. Nick Hague was ground support communicator for the spacewalk. On 22 December 2022, during Cassada and Rubio's next spacewalk, the other iROSA was installed on top of the old 4A solar array.

iROSA 1A/1B

On 9 June 2023, NASA astronauts Steve Bowen and Warren Hoburg exited the station’s Quest airlock and installed an upgraded iROSA on the 1A power channel on the S4 truss section of the station. Bowen and Hoburg removed bolts, deployed the rollers, and installed cables before Hoburg picked up the solar array with assistance from Canadarm2. The two astronauts then installed it on the 1A solar array on the S4 Truss. The array was deployed at 16:32 UTC and was reported to be receiving power. On 15 June 2023, during Bowen and Hoburg's next spacewalk, the other iROSA was installed on top of the old 1B solar array on the S6 truss section.

iROSA 2A/3B The final set of iROSAs, the seventh and eighth, are planned to be sent to the ISS for augmenting the 2A and 3B power channels on the P4 and S6 truss segments after 2025, with preparatory work by Expedition 74 spacewalkers Jessica Meir and Christopher Williams having begun in mid-March 2026. NASA announced in May that they were aiming to launch the final set of iROSAs in fall 2026 (later moved to August 2026), aboard SpaceX CRS-35.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Roll Out Solar Array

Start with the simplest possible case. Write down what Roll Out Solar Array claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, 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 Roll Out Solar Array 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 Roll Out Solar Array 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 Roll Out Solar Array

In research: Roll Out Solar Array appears in astronomy 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 Roll Out Solar Array 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: Roll Out Solar Array is common in secondary-school and first-year university syllabi. It links to neighbouring topics International Space Station, NASA programs, Redwire, so understanding it makes those chapters shorter.
In everyday life: Look for Roll Out Solar Array 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 Roll Out Solar Array in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Roll Out Solar Array 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 Roll Out Solar Array out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Roll Out Solar Array in simple terms?

Why does Roll Out Solar Array matter?

Because it connects several astronomy 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 Roll Out Solar Array?

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 Roll Out Solar Array.