Both U.S. senators from Texas and 10 Houston-area House lawmakers wrote U.S. President Barack Obama April 20 inviting him to visit NASA’s Johnson Space Center.

The invitation follows Obama’s April 15 visit to Florida’s Kennedy Space Center, where he delivered a space policy address defending his plan to cancel the Moon-bound Constellation program in order to focus NASA on developing breakthrough technologies in support of a 2025 manned mission to an asteroid. During his speech, Obama also announced a $40 million economic growth and job creation initiative for Florida and outlined plans to restructure the Orion Crew Exploration Vehicle program to produce a crew lifeboat that would launch unmanned to the international space station.

“We are very pleased to see your administration’s focus on the future of NASA and manned space flight. We look forward to working with you to continue America’s 40 year record of space dominance,” the lawmakers wrote the president, according to a copy of the letter sent to reporters. “However, after reviewing your Fiscal Year 2011 Budget Proposal and listening to your speech at the Kennedy Space Center in Florida, we are concerned that the [Johnson Space Center] and its experienced workforce will not be fully utilized under your proposal for NASA.”

The lawmakers said Obama’s plan to rely “on a promising, yet still fledgling commercial space industry, combined with retiring the Space Shuttle and canceling Constellation will severely diminish the manned space flight program and provide the [Johnson Space Center] with no true mission objective.”

The letter continues: “The United States will be left without domestic manned space flight capabilities or the ability to support the International Space Station (ISS), putting the station at risk of major operational failure well before its planned retirement in 2020. In addition, it is unacceptable for the U.S. to forfeit its dominance in space and risk national security by becoming dependent on the Russians to reach the ISS.”