A rendering on a Dream Chaser spaceplane in orbit.Sierra SpaceSierra House, one of the most sector’s most precious non-public firms, laid off a number of hundred workers and contractors this week, CNBC has realized.A Sierra House spokesperson showed the corporate let pass of about 165 workers on Thursday, however declined to specify the collection of contractors affected. Former Sierra House workers advised CNBC that the layoffs integrated a vital collection of contractors, with the cuts together with masses of team of workers in general.The laid-off workers gained two weeks of paid non-working realize, plus 4 weeks of severance pay and well being care advantages in the course of the finish of the 12 months. Sierra House had about 2,000 workers prior to lowering its group of workers, the corporate spokesperson stated.The Colorado-based corporate, which was once not too long ago valued at greater than $5 billion, is pushing laborious to fly the long-awaited first challenge of its Dream Chaser spaceplane.Sierra House this week shipped the primary Dream Chaser, named Tenacity, for pre-launch trying out at NASA’s Armstrong facility in Ohio. The layoffs started quickly after, the Sierra House spokesperson stated, noting the corporate performed a surge in hiring this 12 months to finish paintings at the Tenacity spacecraft.With Tenacity shipped, Sierra House’s spokesperson stated the corporate is realigning to concentrate on the operations segment of Dream Chaser’s first challenge, in addition to on labeled nationwide safety paintings.The latter a part of Sierra House’s realignment comprises including just about 150 workers with safety clearances from Sierra Nevada Corp., the aerospace and protection contractor owned by way of Fatih and Eren Ozmen, which the distance corporate was once spun out of 2 years in the past. Sierra House’s spokesperson stated the corporate is developing a countrywide safety house staff to paintings on a number of labeled contracts.Sierra House additionally not too long ago misplaced a couple of senior executives prior to the layoffs: COO Jeff Babione, who retired, and Senior Vice President of House Locations Neeraj Gupta. The corporate stated the departures had been unrelated.Two months in the past, Sierra raised slightly below $300 million at a $5.3 billion valuation.Join right here to obtain weekly editions of CNBC’s Making an investment in House publication.Dream Chaser has been in building for years with a purpose to ship shipment and ultimately group to low Earth orbit as a reusable automobile. It resembles a miniaturized NASA House Trip in look and is constructed to release atop a standard rocket and land on a runway like an aircraft.The primary Dream Chaser release was once in the past scheduled for overdue ultimate 12 months, however delays within the building of United Release Alliance’s Vulcan rocket driven again that timeline. Dream Chaser is deliberate to release on ULA’s 2nd Vulcan challenge, with the primary Vulcan release concentrated on December.Dream Chaser has gained NASA contracts to fly seven shipment missions to and from the World House Station.