Some causes look so doomed that all you can do is sit back and admire the pointlessness. So it felt Tuesday, when the Senate Homeland Security and Governmental Affairs Committee looked for ways to make sure government employees aren’t wasting money on travel and conferences. As anyone who’s ever packed a bag knows, the value of a trip or conference is only clear after it’s over.

Changing the wasteful-spending-on-travel-and-conferences culture in government is like changing an aircraft engine during the flight, said Chairman Thomas R. Carper of Delaware. Carper didn’t mean it that way, but that’s about as good an illustration of pointlessness as you’re likely to find.

Ranking member Tom Coburn of Oklahoma said that as a physician, he used to attend conferences. About half of them were good ones and about half weren’t, he said. If even penny-pinching Citizen Coburn can spend his own money wisely only half the time, what chance does the government have?

Not that the two senators weren’t helpful.

Carper, for example, told two administration officials they could save money by booking travel after 6 p.m. And Coburn wondered whether they’d ever used Kayak.com to avoid booking charges. Carper helpfully noted that the sooner they book their trips, the less they cost.

The Delaware Democrat also told them that if a conference is financially justifiable in a given location, it should be held there even if the place is desirable. This could mean government agencies are so spooked by bad publicity that they’re ordering their employees off to Buffalo, N.Y., for conferences or it could mean that Carper’s home-state office isn’t being entirely truthful to him about why nobody is going to Wilmington, Del.

Carper and Coburn should open a travel agency.

Wasteful travel and conference spending became a concern after the General Services Administration spent more than $800,000 on a 2010 Las Vegas conference that included a fee for a mind reader. Hiring a mind reader, incidentally, seems like a good use of government money. Think of the practical uses for one. The problem must have been that they hired someone who DIDN’T read minds.

The IRS had its own publicity fiasco in 2010, including a pricey video in which employees pretended they were on the bridge — mocked up at taxpayer expense — of the “Star Trek” Enterprise. They even had uniforms.

Not to be outdone by Carper and Coburn, administration officials had a few one-star ideas of their own.

GSA Administrator Daniel Tangherlini said the agency uses after-the-event surveys to gauge the benefits of training conferences. He didn’t add that employees who can’t figure out how to, er, skew those answers in favor of sunshine and beaches are in need of more training.

Beth Cobert from the Office of Management and Budget was there to explain how the administration was cleaning up the abuse. Cobert spent many years at McKinsey and Co. Carper wanted to know how McKinsey kept control of travel costs. You start by asking what the purpose of the trip is, Cobert said.

This is an uphill battle.