• The Defense Advanced Research Projects Agency (DARPA) tweeted on Wednesday that it was seeking “university-owned or commercially managed underground urban tunnels & facilities able to host research & experimentation,” raising concern from Twitter users.
  • DARPA’s request is actually related to the Pentagon’s focus on underground warfare in large urban spaces, which it’s devoted at least half a billion dollars to since 2017.
  • The agency told Insider that the request was also related to its SubT Challenge, where teams of researchers show off technology they develop to assist in searching, mapping, and navigating underground spaces.
  • Visit Business Insider’s home page for more stories.

The Defense Advanced Research Projects Agency (DARPA) issued a peculiar request over Twitter on Wednesday, asking for underground tunnels to use for research – as soon as possible.

Though DARPA’s request managed to spook Twitter users, DARPA told Insider that the request is related to technology development for underground combat and search-and rescue operations.

While President Donald Trump looks to create a Space Force – an entirely new military branch – the Pentagon itself has put more than half a billion dollars into technology and training to compete on underground battlefields.

The Defense Advanced Research Projects Agency asked universities and colleges for underground tunnels to use for research.

Foto: Soldiers of 2nd Stryker Brigade Combat Team, 2nd Infantry Division, provide security during subterranean operations training, May 17. Lancers of 2nd Stryker Brigade Combat Team, 2nd Infantry Division, with the assistance of a Mobile Training Team from the Army’s Maneuver Center of Excellence, completed a 5-day exercise focused on subterranean operations, at a remote underground facility in Washington State, May 14-18.sourceStaff Sgt. Michael Armstrong / US Army / DVIDS

“Attention, city dwellers,” DARPA tweeted. “We’re interested in identifying university-owned or commercially managed underground urban tunnels & facilities able to host research & experimentation.”

The agency noted the short notice of the request - it asked for responses within two days - and specified that it was seeking "a human-made underground environment spanning several city blocks" which includes "a complex layout & multiple stories, including atriums, tunnels & stairwells."

While the Trump administration is increasingly looking to the skies and pressing for a Space Force, DARPA is focusing on operations underground.

Foto: Scientists watch soldiers sample simulated leaking chemical weapons in an underground facility in order to get a better idea of both the bulky protective gear soldiers must wear as well as the dark, constrained environments they sometimes work in.sourceStacy Smenos, Dugway Proving Ground / DVIDS

In the agency's online request for information, DARPA specifies that it's trying to understand how technology could be used for rapid mapping, search, and navigation operations, likely in the case of urban conflict or disaster-related search-and-rescue operations.

"Complex urban underground infrastructure can present significant challenges for situational awareness in time-sensitive scenarios, such as active combat operations or disaster response," Jared Adams, a spokesperson at DARPA, told Insider via email.

The request comes out ahead of DARPA's Subterranean Challenge.

Foto: The Ultra-Light Robot employing its “arms,” which can be used to climb small obstacles such as stairs, July 3, in Stafford, Virginia. In the fourth quarter of fiscal year 2019, the Corps will field the Ultra-Light Robot—a small, mobile robot system that enables explosive ordnance disposal Marines to manage or destroy improvised explosive devices or conduct various other reconnaissance activities.sourceMatt Gonzales / US Marine Corps / DVIDS

The Subterranean Challenge, or SubT Challenge, invites teams of researchers from all over the world to compete and find technological solutions for underground operations. The teams use locations - like the ones DARPA requested information about - to test technologies that can search and navigate in underground terrain where it might be too difficult for humans to go.

Teams in the systems competition focus on technology like robotics that can physically search and navigate in an underground terrain. On the virtual track, teams compete and develop software that can be used to assist in simulations of underground operations.

The urban circuit of the SubT challenge will take place in February 2020, hence the request for urban underground space.

Foto: Soldiers with 3rd Armored Brigade Combat Team, 1st Cavalry Division provide security while clearing an underground complex during dense urban environment training. The training, provided by a mobile training team from 3rd Squadron, 16th Cavalry Regiment out of Fort Benning, introduces tactics and techniques to the force to prosecute operations within dense urban terrain and populated urban centers.sourceCapt. Scott Kuhn / DVIDS

"As teams prepare for the SubT Challenge Urban Circuit, the program recognizes it can be difficult for them to find locations suitable to test their systems and sensors," Adams told Insider.

"DARPA issued this RFI in part to help identify potential representative environments where teams may be able to test in advance of the upcoming event."

The military has become more aware that it needs to develop technology and strategy to fight in an underground, urban setting.

Foto: Soldiers perform evacuation procedures at Fort Hood's underground training facility. The training is part of a week-long training teaching Soldiers how to fight, win and survive in a dense urban terrain.sourceSgt. Jessica DuVernay / DVIDS

Historically, underground warfare has been the domain of special operations troops like Navy SEALs. But military researchers predict that this kind of warfare will be too much for special operators alone to navigate, particularly if dealing with an adversary like China or Russia, which both have extensive underground space. China in particular uses vast underground complexes to store missiles and its nuclear arsenal.

"We did recognize, in a megacity that has underground facilities - sewers and subways and some of the things we would encounter ... we have to look at ourselves and say 'OK, how does our current set of equipment and our tactics stack up?'" Col. Townley Hedrick, commandant of the infantry school at the Army's Maneuver Center of Excellence at Fort Benning, Georgia, said in an interview with Military.com last year.

The military has encountered underground facilities before — some Vietnam War-era special units explored tunnels dug by the Viet Cong.

Foto: Members of Iraqi rapid-response forces inspect a tunnel used by ISIS militants as underground training camp in the hillside overlooking Mosul, Iraq, March 4, 2017.sourceREUTERS/Alaa Al-Marjani

ISIS militants also used tunnels in Iraq and Syria. In Israel and Lebanon, Hezbollah fighters used underground tunnels to launch attacks in Israel